The Facts on the Department’s Costs to Implement Washington’s Income Tax on Millionaires

Since the passage of Senate Bill 6346 during the 2026 legislative session, we have seen some misconceptions about the Department’s costs to implement this bill that we want to clarify for the public. This is a large, multifaceted piece of legislation that will take several years to implement and the fiscal note that details the costs is complicated. In the interest of making sure everyone has the facts, we’ve addressed the most common misconceptions below.

Claim: It will cost the Department of Revenue over $275 million a year to administer the tax.

Reality: Actual costs are approximately $30 million a year once the tax is in effect.

That $30 million includes many things such as employee costs, system operation/monitoring/maintenance costs, and increase in support functions. In addition to establishing the income tax on millionaires, Senate Bill 6346 significantly expands the Working Families Tax Credit (WFTC) program, a tax refund for low to moderate income Washington workers and their families, by removing age restrictions and expanding qualification thresholds. The $275 million number cited above includes costs to administer the income tax and the expanded WFTC program, as well as anticipated refunds to WFTC program recipients which are over $231 million.

Claim: The Department of Revenue is hiring over 300 employees to administer the tax.

Reality: There will be approximately 130 employees responsible for administering and enforcing the tax.

As with the first claim, the 300 number covers everything required by the bill, not just the implementation of the income tax on millionaires. For example: expanding the WFTC program will more than double the amount of those eligible for a tax refund, jumping from 350,000 to more than 800,000 recipients. The WFTC division will hire an additional 100+ employees to meet this demand.   

Claim: You only hire that many employees if you are going to expand the income tax to everyone.

Reality: This number of employees is what the agency will need to administer the tax as written.

The agency only considered the law as written when making these estimates; it does not consider potential expansion. The currently planned number of full-time employees is what it will take to administer an income tax on income over $1 million for the potentially 21,000 taxpayers subject to it.

Given that this is a new tax, the Department is committed to providing information to help the public understand more about it.